Armor rod clamp



Sept- 5, 1950 A. H. TESSMANN 2,521,192

ARMOR ROD CLAMP Filed March 11, 1947 '7 INVENTOR.

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Patented Sept. 5, 1950 ARMOR ROD CLAMP Alfred H. Tessmann, Chattanooga, Tenn. Application March 11, 1947, S's-arm. 733,847

2 Claims. (01. 24-31223),

My invention contemplates and provides improved clamps admirably suitable for securing armor rods to their associated conductors.

Modern electric power conductors usually are in the form of cables consisting of a plurality of wire strands twisted around a center strand.

These conductor cables, which ordinarily are formed of aluminum Wire, are not well adapted to withstand vibration at or near the points where they are attached to insulators. Therefore, it has become approved practice to reenforce these conductor cables, against the effects of excessive vibration, by wrapping them with armor rods in the regions of their attachment to insulators. Sometimes these armor rods have been preformed helices of hard drawn wire or other suitable material which have been concave-convex in transverse section and have presented their concave surfaces to the conductor cable (for example see U. S. Patent No. 2,275,- 019). More commonly, however, the armor rods have been strands of heavy gauge round wire, usually of aluminum; several strands of this heavy gauge wire being twisted around the conductor cable to sheath it (for example see U. S. Patent No. 2,210,587). In each case the armor rods are secured to the conductor by clampsthe common practice being to provide a clamp at or near each end of each group or cableslieathing armor rods. of improved clamps for securing armor rods to their associated conductors that my instant invention is concerned.

Among the objects of my invention may be enumerated the following:

(1) A generally improved clamp for the purpose stated;

(2) A clamp for the purpose stated consisting of cooperating parts, capable of being economically manufactured, which readily may be interengagedwith each other in girdling relationship to a group of armor rods and, after being suitably deformed with an appropriate tool, become reliably secured to each other and squeeze the armor rods with predetermined optimum pressure;

(3) A clamp for the purpose stated composed of two identical halves;

(4) A clamp for the purpose stated consisting of two identical halves provided with inte- It is with the provision gral means for inter-engaging them with each other;

(5) A clamp for the purpose stated which when properly applied to a group of armor rods defines a passage occupied by such armor rods 2 which is characterized by outwardly flaring or belied ends;

6) A clamp for the purpose stated which suitably and desirably may be formed of a malleable or deformable metal such as aluminum or an aluminum alloy;

(7) A clamp for the purpose stated which, when occasion requires, readily may be pried asunder. with a screw driver nib or like part.

" presented by a suitable tool.

Further objects, features and advantages of my invention will appear from the following descriptiornin which a preferred embodiment of the: invention has been described in conjunction with the accompanying sheet of drawings. The appended claims are to be accorded a range of equivalents consistent with the prior art.

In the accompanying sheet of drawings:

Fig. 1 is a side elevational view illustrating one of my improved clamps as it appears after its components have been interengagcd with each. other in girdling relationship to a group of armor rods but before those components have been distorted, as hereinafter explained; to prevent their accidental separation and to cause them to squeeze the armor rods with an optimum predetermined pressure;

Fig. 2 isan end view, partly in section and. partly in elevation, which may be regarded as taken on the line 2-2 of Fig. 1;

Fig. 3 is an inner face view of one of the identical halves or units whereof the clamp is composed;

Fig.4 is an end elevational view of one of those halves or units; and I Fig.5 is a view similar to Fig. 1 but illustratingthev clamp as it appears after being deformed to prevent accidental separation of its components and to squeeze the embraced armor rods as aforementioned.

Similar characters of reference refer to similar parts throughout the several views.

. Referring first to Figs. 1 and 2, at A I have depicted a group of armor rods in conventional relationship to a conductor cable 13. Usually, but not necessarily, the conductor cableB will becomposed of aluminum wire and the armor rods A of relatively heavier gauge aluminum.

wire.

A. clamp embodying my present invention consistsof two cooperating identical halves or units 6,,which are formed of a metal, preferably alu minu'm or an aluminum alloy, which is rnal--- leable or deformable as and for the purpose hereinafter described. In end View each of the:

halves or units 6 is concave-convex, the convex exterior surface 1 of such half or unit being semi-ovoidal and its concave interior surface 8 being semi-cylindrical.

Each of the halves or units 6 is provided with two pairs of longitudinally extending plane faces 9 and 9a and I and 1011. When each unit 6 is assembled with an identical unit to constitute an armor rod clamp, its faces 9 and 9c are adapted to abut orlie in immediate jufxtzi'posigtion to the faces [0 and Illa of the other unit; and similarly its faces [0 and Illa are adapted to abut or lie in immediate juxtaposition to the faces 9 and 9a of the other unit.

Projecting outwardly from between the plane surfaces 9 and 9a is a longitudinallyextending bead ll and bounded by th plane surfaces l0 and Illa is a longitudinally extending groove 1?, When the unit 6 is assembled with an identical unit to constitute a conductor cable clamp, the bead I l of each unit cooperates dovetailwise with the groove [2 of the other unit, v N a Each unit 6 is provided adjacent its bead II with a longitudinally extending recess I3. I,

In order to provide an armor clamp gtwo of the identical halves or units 6 are caused to inter-engage each other ifi girdling relationship to the armor rods A and their sheathed conductor B, as depicted in Figs 1 and 2 lt will be noted that the recesses 3, beingopposed' by plane faces I 0, are now outwardly opening slots. 'Ihese slots retain their identityas such despite" the deformation of the clamp nowto' be discussed. I

The clamp consisting of the two inter-engaged halves or units dis now squeezedibfy and between the jaws of any suitable deforming tool (not shown) which acts to' provide circunjifrentially extending concavities fe in the convfx exterior surfaces f and resultantcircumferentially ex; tending convexities l the onc'ave slurfac'esia, see Fig. 5; The deforming tool may or may not be of the so-called' fliot linefvarietiz, as" desired Such deformation of the eiams-tends a h' bead H and its cooperating groove l 2 laterally of themselves andinwardly toward the clamp passage occupied by th armor rods and die pendably locks each head I'l' agamstenawise dis placement from the'groove l2 by which it is received, causes the cla mp tq squeeze meat rods A with an optimum pressure predetermined by the properly limitedamountof c am i' deformation which the" deforming 1:061 iscapabl of eifecting, and accords ou wardly flariiig or belied ends Is to thecla'n'ip assage dccupijec'r by the armor rods. The length'of sii'cl i clamppas: sage should not be substantially less than its diameter; desirablyf slich lengtli' afid diameter are substantiallyequal beforedeforination of the clamp, as illustrated; v V V f When and if it becomes necessarytoffeleaisethe armor rods from thej'einbrace of steamy-pimp the latter effectively maybe opned by insert. ing in either of it's otitivardly opening"; slotsa screw driver nibor'lili'e part'carried by a hot line or other suitableimplementlj v That the clamp of' my invention, in its prg f erred embodiment; consists'of but twd'parts and they identical, as" distinguished from prior clamps usually consisting of a multiplicity of non-identical part'sl is 0ft great practical advantage; so also is the fact'that myclanip; when deg formed by an"- appropriate tool; cannotf overesqueeze and thus damagfthe armor'rod's and the o u q h at s l b as i ,v pea Ql frequently have done; and so also isthe fat'tliit the outwardly flaring or belled ends of the clamp prevent cutting and minimize chafing of the armor rods at the points where they emerge from the clamp.

It is not absolutely essential that the surfaces 1 and 8 have dissimilar curvatures. For example, they both may be semi-cylindrical surfaces struck from a common center. However, the relationship of these surfaces a s depicted in the drawfilg's, affordsample room between. their correspondin extremities for surfaces 9 and 9a and bead II, and for surfaces In and Mia and groove l2 while still maintaining the total mass of unit 8 desirably low. I Having thus illustrated and described a preferred embodiment of my invention, what I claim as new and desire to secure by Letters Patent of, the United States, is:

1. The method of clamping a group of conduc- 1? 1 31 9 n l' am e d tq com risi bl rin lMSii Peitbea fi 0. 16 12: t ilih i s s eemds it a ality of, arcad un t d e efb e mall ble metal ent re nd q-end by ax ll i dinedo e: a l d. on ue findsrQWe at i co i u edf t ioel n td i m n he. un s e domsi l iv .sime sfi e e loses. a t by el te m r l ir t ve. re su nwa l 91 i te me d etep i ens Qf h m efl e of t e. u aie ress e s r in .bsc en in t encased to ues, i r s' b9199 helmits a ns mov m n inl lo n s ameai l with aqhip r. ld is tu t ll if the .s lq iet .an ser na q om-9 cm the malleable metal of the unitsto the rods at the i e o t 't fio tr s t j wh lc sin ltn inner edges olf the malleable units to flare away ei ih edie eeta 9 2112 m i na i c nduct r mm: io s em lat v a oun d e ten in a o s id e e'qleiri @1 55 a co lar nthl 'hne i 'd'i to r anldrods and consisting of a plurality of aroue iauni s .o ume a lei etal nn ed n t e g by a'xially extending dovetailed tongues I and grooys which are a interlockingly deformed against] their separation, the armor rods, and h ir. ass ated conductor. bei g..con' r ive y squeezed by said collar with the malleable: metal 6 units conforming to the armor rods atia e of; greatest, constriction and with' the iriner edges Lof the units flaring. away from their adjacent arm'br' rods.

ALFRED H. TESSM'ANN.

REFERENCES CI'IED' 'lhe following references are'of record in the file Of this palfrlt! UNITED STATES PATENIS n; Nalne Date 599429: Johnson Noy. 21, 1893, 555,512; J hnsqr'i Mans, 1896 6503360v Mc'lighe 'June 5] 1900 917,729 11is ec; 6; 1910 1,151,131 stanipe1-' Aug, 24, 19,15 332,626 Henegar' Mar, 2; 192,0 ,49 qab iel, .May 6, 19 4 1;770,971 Conner June 22, 1930 1,858,284, Schwartz May 17, 1932 Zl09,'5 l7,j Xenisj Mar. 1, 19.38 2,312,989' Laverack Mar. 2', 1943 FOREIGN PATENTS 

